1. Field of the Invention
The present invention relates to liquid dispensing spray guns and more particularly to an acoustic material applicator for repair spraying small areas of damaged walls and ceilings.
It is common practice in building construction to cover wall and ceiling areas with a coat of acoustic material comprising a viscous mixture containing fibrous materials or small particles of expanded synthetic resinous material, such as Styrofoam. During construction this acoustic material is usually applied by a spray gun supplied with the material from a reservoir with air being supplied by a compressor. The equipment is necessarily bulky and is not easily moved from one location to another. After initial application, the acoustic coating is frequently damaged accidently during further construction requiring the damaged area to be repaired. Repairing the damaged area presents a problem not only by necessitating returning the spray equipment to the location to be repaired but principally for the reason the initial applicator gun sprays a relatively large area and is not easily controlled for spraying a small damaged area thus resulting in recovering that area surrounding the damaged surface and a mismatching of the texture or color, if colored, so that the repair job is obvious.
This invention provides a relatively small spray type applicator similarly actuated by a source of air under pressure and is easily controlled to apply a relatively small quantity of the viscous material, The amount of material sprayed on a wall surface being controlled by manual pressure applied to a squeeze-type container so that an excess of the material is not applied indiscriminately to the surface around the area being repaired.
2. Description of the Prior Art
The most pertinent prior patent is believed to be Italian Pat. No. 559,900, issued MAR. 27, 1957 (Grossi). This patent discloses an aspirator for spraying a liquid from an attached container with the liquid flow being controlled by a valve.
The principal distinction of this invention over the above-named patent is the truncated conical configuration of the chamber having its larger end disposed toward an orifice through which an air tube conducts a stream of air. The relationship of the port diameter, admitting the material be be sprayed, to the transverse cross sectional area surrounding the air tube within the truncatcated wall must be on a ratio of at least one-to-one for movement of viscous material to be sprayed.
Other prior patents relating to this invention are U.S. Pat. Nos. 311,425; 1,501,432; 2,368,536; 3,052,417; 3,386,664 and British Pat. No. 431,706 (Lennox) issued JULY. 15, 1935, but not believed to be as pertinent as the Italian patent, generally relate to aspirator type spraying devices some of which employ squeeze-type containers for the purpose of ejecting or spraying discrete portions of fluid on a small area or for painting, cleaning or other types of liquid dispensers. None of these devices, it is believed, are capable of spraying a viscous material, such as acoustic texture material, for the reason acoustic texture material is not easily applied in discrete amounts.